List of Suggested Experiments

From EM Drive
Jump to: navigation, search

This page compiles suggestions for as-yet untested variations in experiment designs for EmDrive testing. When possible, links to the original suggestion and a brief description of the justification for this test are provided.

Note: For purposes of this list, the baseline for experimentation is considered to be a copper frustum with either a magnetron or coaxial RF feed operated at approximately 2.45Ghz, similar to Shawyer's Feasability Study

Design/Shape Modifications[edit]

  1. Replace solid endplates with a circular grid design similar to the endplates used by Cullen in his 1950's waveguide experiments,[1] or a mesh as the one used for the glass windows in home-microwave-ovens, having a spacing between mesh or grids small enough such that only wavelengths smaller than that can get through.[2] Purpose: to allow convection through the frustum, eliminate buoyancy, thermal jet effects, natural thermal convection currents, and other gas effects.
  2. Place ferrite beads in the frustum, either one large one next to an endplate or a pattern of them along a line in the longitudinal direction. Purpose: to increase attenuation gradient in TE modes, having an axial magnetic field.[3]
  3. Build Large end plate out of Metglas or a similar material with high magnetic permeability like cast iron or any ferrite.[4] Purpose: to test de Aquino's conjecture regarding the effect of power dissipation at the end faces of the truncated cone.
  4. Place a ruby inside near one of the ends to emit at 2.4 GHz as used in solid state Masers.
  5. Fill the frustum with ammonia gas to emit at 24GHz. Purpose: To produce maser-like amplification inside the frustum.[5] Warning: If using ammonia, please follow appropriate safety procedures[2][3].
  6. Place a dielectric next to the Small end, as done by NASA Eagleworks, who found extruded HDPE to be slightly better than extruded PTFE. Do not use molded (instead of extruded) polymers. NASA Eagleworks found that Neoprene rubber performed poorly as a dielectric in the EM Drive, as it resulted in considerably less thrust.
  7. Separate resonance and attenuation chambers. Purpose: Proposed by WarpTech as a test of his theory.
  8. Apply a silver or gold coating to the inside of a copper frustum. Purpose: The increase microwave reflectivity, and therefore increase Q factor.
  9. Measure the force on two cylindrical resonant wave guides (lowest transverse electric mode) tuned to resonate at the same frequency (one is adjustable) with their flat plates separated by a quarter wavelength. The current in cavity one is out of phase with cavity two by 90 degrees. [6]
  10. Test a pillbox-shaped cavity similar to the Cannae drive and compare results to an EmDrive frustum tested with the same experimental setup.
  11. Place two vent tubes for heated expanding air that bisect equal volumes on the resonating cavity. When air heats up it is exhausted perpendicular to thrust and displaces air volume equally so as to eliminate thrust from pressure gradients. [7]
  12. Test the EmDrive's inertial reaction to an outside force by using a known mass on to pull agains the EmDrive while it is powered.[8]
  13. Test the EmDrive at both 50hz and 60Hz duty cycles for the Rf input, as well as a 100% on duty cycle.[9]
  14. Link two magnetrons together in a "slaved" configuration to amplify the Rf signal to an EmDrive.[10]
  15. Use accelerometer for rotational feedback on the Gunn diode bias to optimize for chamber resonance
  16. In consideration of [11] suggest filling the EMdrive cavitity with pure hydrogen to see if the thrust changes.
  17. Insert fibre optic cable. Hook up to photon counter and/or spectrum analyzer.

Virtual Frustum EMDrive[edit]

Delivering Scalable, Vectorable, High-Reliability, High-Output Thrust in Real-World Applications

It is time to dispose of EMDrive's material frustum. That chunk of energy-wasting metal is an awful obstacle to further development and prevents all existing EMDrive implementations from scaling up and otherwise being useful in real-world, realtime, variable, vectorable, reliable high-power thrust applications.

Existing physical frustum designs are the first of two quantum design steps. They are solid forms which are easy to work with and are physical concretizations of an entire field of variables in solid material form. This concretization makes calculations simple but imposes fundamental physical constraints on their usable performance.

There is no need to waste so much energy to bounce microwaves around in order to achieve some kind of directional ratio. Raising the Q-Factor of the material frustum is costly. It involves expensive superconductors which require heavy, failure-prone supercooling machinery to work. In case of cooling failure due to unexpected interruption their Q-Factors drop and due to rapidly higher energy absorption they melt and/or vaporize thus destroying the device.

A better method to achieve the much-vaunted high power and enhanced device tunability thus usability is to eliminate the material frustum entirely. This method uses carefully-directed microwaves from solid-state nano-structured surface emitters arranged to near- or atomic precision. The output waves are so precisely arranged in space, frequency, time and phase that they self-interfere in the spacial shape of an ideal frustum or other ideal physical reflective structure.

The Q-Factor of self-interfering microwaves is limited only by the perfection of their spacial geometric arrangements, frequencies, phases and timings.

There is no expensive superconducting mass and associated cooling equipment.

There is zero energy loss due to material absorption of microwave energy. This fact itself raises the Q-Factor to values exponentially-higher than any material frustum could hope to achieve.

Future EMDrives will be enormously powerful and will propel hovercrafts, ocean ships and spacecrafts including air carriers and suborbital platforms. They will finally achieve the dreams of the exhausted and crude currently-existing mass-ejection drives which are now fully outdated and a sinkhole for further financial investment.

Successful high-power realtime-drive systems will not utilize physical frustums because the required size of such frustums to match power requirements will mean that their shapes will deform due to gravitational shifting, thermal effects, vibrations and more. Not to mention the high financial cost of the required material and cooling systems.

These fast and slower deformations will murder their Q-Factors even if their material construction is superconductive, thus obviating their use for such applications.

Take for example this world's large Radio Telescopes and Optical Telescopes. They do not have to contend with high input powers but even so it is Hell to design them to maintain their shapes within the accuracy required for useably-accurate waveform collimation and focussing.

In these cases computer-controlled adaptive dynamic realtime reconformation systems must be used to manipulate arrays of subelements to keep the entire unit focussed. Even this is complex and costly and these systems are not dealing with massive power inputs nor accelerations on moving platforms nor rapid thermal effects from the varying power inputs, phases and frequencies required of a real-world realtime drive system.

These effects added together will render infeasible the use of large-scale high-power realtime-variable EMDrive thrusters based on physical frustums.

Virtual Frustums do not experience these problems. Phase, time and geometric parameters of a Virtual Frustum do not vary with angle relative to planetary gravity, acceleration or temperature. Virtual Frustums are inherent superconductors and are physically superfluid.

When maintained at realtime adaptivity with massively-parallel sense-feedback arrays into a parallel computation system running a realtime RF simulation the Virtual Frustum's phase boundary is dynamically maintained in a state of complete optical opacity to relevant waves within its virtual cavity. This opacity is not absorptive but rather completely reflective.

There are two not-mutually-exclusive ways to design a Virtual Frustum:

1. A purely passive Virtual Frustum uses only wave self-interference to generate a continuous virtual reflective surface.

2. A purely active system uses any number of opposing emitter arrays to generate geometrospacially-opposing waves.

At the surface of this Virtual Frustum, incoming microwaves form a standing wave which does not move. The standing wave becomes a bidirectional electromagnetic reflector with infinite Q-Factor.

This standing wave does not suffer from entropic thermalization thus its losses are near-zero. The only losses it obtains are the results of imperfect wave frequency, phase, spacial distribution, amplitude calibration of the entire wavesystem.

Realtime Velocity & Acceleration Measurement

It is both a requirement of the Virtual Frustum System and an independently-exploitable ability to measure velocity and acceleration in realtime by its fields of nanoarray antennas which constantly sense microwave backpressure. Backpressure changes in space and time are transmitted via ultrafast parallel link to an off-the-shelf multicore parallel computer which continuously runs an RF waveform simulation of the system. Roundtrip latency is compensated by forward precompensation.

This data provides the required inputs to keep an accurate realtime model of the Virtual Frustum System. It allows the controlling computer to precisely calibrate all microwave emitters' frequencies, phases and powers to achieve the requested thrust.

Aside from propulsive systems, very low-power Virtual Frustum Systems can be used solely for precise low-latency measurement of velocity & acceleration. Three-dimensional nanoantenna-arrays allow the integrating computer running the RF simulation to determine parametric motion and acceleration in three dimensions at realtime.

Thrust Vectoring

Further, unlike a Physical Frustum, the Virtual Frustum System's entire thrust output is realtime-vectorable without physical movement of any material thus eliminating motion latency and any possible mechanical failure. Instead the shape of the Virtual Frustum is modified in realtime via aforesaid techniques by the controlling computer. The available spacial configuration-space of a Virtual Frustum is limited only by the physical shape and characteristics of the solid-state emitter arrays.

Output Calibration

Physical frustums are limited in their ability to adaptively modulate their thrust-generating output power and absolutely limited in their ability to vector thrust. The physical frustum must be mechanically rotated to vector thrust.

Shawyer has designed a two-part frustum which can be mechanically extended/retracted via electrically-operated mechanisms such that it can achieve better resonance within the wide range of drive characteristics he anticipates will be required in a real-world thrust application.

However, his design is still very limited and worse, based on high-latency, failable, geometry-limited mechanical actuators. In short a gimmicky trick and one that is fundamentally-unsuited for the task.

The [b][i]Virtual Frustum does not suffer from these deficiencies. It is not limited by mechanical constraints nor by the vagaries of mechanical actuators.

The controlling computer running the realtime RF simulation and using low-latency highly-parallel feedback-sense input from the nanoantenna arrays modulates the output characteristics of the emitter arrays such that thrust magnitude, vector and timing match the requested values received by upstream components of the flight system.


Is it actually possible to create a Virtual Frustum?

The first question which could be asked is can microwaves form a virtual self-reflector. They can:

A computational and statistical framework for multidimensional domain acoustooptic material interrogation]

All that is required is that the Virtual Frustum's boundary standing wave be harmonically opaque which will result in total internal reflection of impinging microwaves. It will behave in a manner identical to an ideal superconducting metallic reflector.

The Virtual Frustum is a realtime computationally-controlled ideal [b][i]microwave mirror at select frequency(s).

Harmonic opacity is achieved by ultraprecise wave alignment in amplitude, time, phase and space. That is achieved with precise nanoemitter arrays and rapid parallel computation. These costs are small and justifiable considering the enormous size and immeasurably-large feasible scaleup implied by the Virtual Frustum System.

The Virtual Frustum System implementation relative to its predecessor the Physical Frustum System is analogous to the advance Polywell-mode plasma containment made from its predecessor the Fusor. The Fusor uses wire grid plasma containment which is inherently limiting and prevents its power and density from being upscaled to reach power-generation level activity.

Polywell utilizes a smarter method of plasma containment: a virtual 'well' created by smart EMF field design. The analogy to the Virtual Frustum System is merely a rough comparison but it is compelling in that both the Fusor and Physical Frustum systems' successors eliminate a metallic element subject to heating and current effects thus achieving high-power scalability and tunability.

Indeed, this system is the only implementary path which leads to affordable, flexible, dynamically-tunable, vectorable, reliable and most importantly ultra-high-power and ultra-high-efficiency thrust systems with Q-Factors heretofore only dreamed about and endlessly discussed by so many hopeful individuals day after day with little fundamental progress achieved thus far.

Experimental Measurement Setups[edit]

  1. Use smokesticks to test for out-gassing and hot air jets from the frustum[12]
  2. Test on a zero-g simulator flight.
  3. Cavendish Pendulum[13]
  4. At a set power measure the force at resonance, then vary the frequency slightly and see if force rises as resonance drops. [14]


  1. Forum post by Rodal
  2. Forum post by demofsky
  3. Forum post by Rodal summarizing several prior posts.
  4. Forum post by Flyby referencing earlier posts.
  5. Forum post by aero, in response to Rodal's explanation of the history of maser development.
  6. Forum post by dustinthewind, A suggested experiment.
  7. Forum post by dustinthewind, A suggested experiment modification
  8. Forum post by arc
  9. Forum post by TheTraveller
  10. Forum post by ElizabethGreene
  11. [1]
  12. Credit to @Seeshells
  14. Forum post by dustinthewind Stated as a question.